.TH dtruss 1m  "$Date:: 2007-08-05 #$" "USER COMMANDS"
.SH NAME
dtruss \- process syscall details. Uses DTrace.
.SH SYNOPSIS
.B dtruss
[\-acdeflhoLs] [\-t syscall] { \-p PID | \-n name | command }
.SH DESCRIPTION
dtruss prints details on process system calls. It is like a DTrace
version of truss, and has been designed to be less intrusive than
truss.

Of particular interest is the elapsed times and on cpu times, which
can identify both system calls that are slow to complete, and those
which are consuming CPU cycles.

Since this uses DTrace, only the root user or users with the
dtrace_kernel privilege can run this command.
.SH OS
Solaris
.SH STABILITY
stable - needs the syscall provider.
.SH OPTIONS
.TP
\-a
print all details
.TP
\-b bufsize
dynamic variable buffer size. Increase this if you notice dynamic
variable drop errors. The default is "4m" for 4 megabytes per CPU.
.TP
\-c
print system call counts
.TP
\-d
print relative timestamps, us
.TP
\-e
print elapsed times, us
.TP
\-f
follow children as they are forked
.TP
\-l
force printing of pid/lwpid per line
.TP
\-L
don't print pid/lwpid per line
.TP
\-n name
examine processes with this name
.TP
\-o
print on-cpu times, us
.TP
\-s
print stack backtraces
.TP
\-p PID
examine this PID
.TP
\-t syscall
examine this syscall only
.PP
.SH EXAMPLES
.TP
run and examine the "df -h" command
# 
.B dtruss 
df -h
.PP
.TP
examine PID 1871
# 
.B dtruss
\-p 1871 
.PP
.TP
examine all processes called "tar"
#
.B dtruss
\-n tar
.PP
.TP
run test.sh and follow children
#
.B dtruss
\-f test.sh
.TP
run the "date" command and print elapsed and on cpu times,
#
.B dtruss
\-eo date
.PP
.SH FIELDS
.TP
PID/LWPID
Process ID / Lightweight Process ID
.TP
RELATIVE
relative timestamps to the start of the thread, us (microseconds)
.TP
ELAPSD
elapsed time for this system call, us
.TP
CPU
on-cpu time for this system call, us
.TP
SYSCALL(args)
system call name, with arguments (some may be evaluated)
.PP
.SH DOCUMENTATION
See the DTraceToolkit for further documentation under the 
Docs directory. The DTraceToolkit docs may include full worked
examples with verbose descriptions explaining the output.
.SH EXIT
dtruss will run forever until Ctrl\-C is hit, or if a command was
executed dtruss will finish when the command ends.
.SH AUTHOR
Brendan Gregg
[Sydney, Australia]
.SH SEE ALSO
procsystime(1M), dtrace(1M), truss(1)

